PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = "2018-10-16 GEO:SHS Added pointer to README.TXT for the PDS4 archive" RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2015-10-09 NOTE = "AAREADME.TXT describes this volume." END_OBJECT = TEXT END PLEASE NOTE: This archive has been migrated from PDS3 to PDS4. The contents and directory structure of the PDS3 archive have not changed, but PDS4 metadata in the form of XML files have been added. The file README.TXT in the root directory has more information. The file you are now reading, AAREADME.TXT, was written for the original PDS3 archive and does not have information about the PDS4 additions. ---- Original contents of AAREADME.TXT are below this line. ---- MESSENGER X-Ray Spectrometer Uncalibrated Data Archive Prepared for the Geosciences Discipline Node of the Planetary Data System ======================================================================== Introduction ======================================================================== This volume contains uncalibrated (EDR) data and associated documentation from the MESSENGER X-Ray Spectrometer (XRS). A complete description of the design of this volume is given in the XRS EDR software interface specification. An electronic copy of this document is located on this volume in the /DOCUMENT directory. This volume is intended for the use of scientists and students in the study of the geography and geochemistry of the planet Mercury. The data may be used for research and publication. ======================================================================== Volume Format ======================================================================== All science data are located under the DATA directory. The INDEX directory contains a listing of all of the data products included on this volume. The CATALOG directory contains PDS documentation describing the mission, spacecraft, instrument, and data set. These include: MISSION.CAT MESSENGER mission description INSTRUMENT_HOST.CAT MESSENGER spacecraft description INSTRUMENT.CAT XRS instrument description DATASET.CAT XRS uncalibrated data set description REF.CAT MESSENGER mission reference information, including XRS references. PERSON.CAT XRS personnel contact information. Additional information on volume organization is given in the EDR SIS (described above), and in section the 'Volume Contents' below. ======================================================================== File Formats ======================================================================== The data files on this volume are provided in flat IEEE binary format (extension .DAT) as well as ASCII table format (extention .TAB). Each data file is also accompanied by a detached PDS label file (extension .LBL), an ASCII file containing information describing the data file and data record format. Catalog files (extension .CAT) are provided in ASCII format. Document files describing the volume and the data are given in ASCII format, HTML, and PDF formats. Text files and detached label files contain 80-byte fixed-length ASCII records, with a carriage-return character (ASCII 13) in the 79th byte and a line-feed character (ASCII 10) in the 80th byte. This format allows the files to be read by MacOS, DOS, UNIX and VMS operating systems. Note that while both label and catalog files are ASCII, some operating systems will not recognize the .LBL and .CAT extensions as ASCII types. It may be necessary to either remap these extensions as ASCII in the system or text browser, or else to open the files from within the text browser. ======================================================================== Volume Contents ======================================================================== Directory Structure and Contents for XRS EDR Data Archive Volume The following illustration shows the directory structure overview for the XRS EDR archive volume, which bears the PDS-assigned volume ID MESSXRS_1001. This volume contains the XRS EDR data products, supporting documentation, and any additional files required for the volume to be compliant with PDS standards. The content of the volume is expected to be updated with periodic releases according to the schedule found in the MESSENGER Data Management and Archiving Plan (DMAP). Revised EDRs (if needed) will also be delivered according to the same schedule. Revised EDRs will have an incremented version number in the PDS label. Directory Structure Overview: ___________________________________|____________________ | | | | | |